non return valve in diesel feed line to engine

[catmandoo]

When changing the fuel filters on my diesel engine i have a problem priming the filters after the change because the fuel is normally lifted from the bilges about 1 metre to the filters and engine. When I break open the primary filter fuel runs back into the tank . The Racor primary filter has a priming pump but it will not really work on air and needs fuel to get the suction needed to prime the filter so I have been considering fitting a non return valve in the 10 mm line close to the tank . any advice about which type of NRV to use , vertical or horizontal .brass or plastic Any problems using with diesel in a 10 mm feed line ?

Not a problem with the secondary filter because it is on the discharge of the engine fuel pump not its suction

 

[cimo]

hello c
never came across fuel line check valves - so no advice to give on that.
thought I'd post to suggest filling the primary filter with fuel directly from your spare can. it speeds things up no end.
rgds
c

 

[VicS]

No tank outlet valve that you could shut before changing the filter?

could fit one rather than a NRV

Surprised the priming pump does not stop the fuel running back.

 

[NorthUp]

Will it be easier to fit a simple ball valve (lever operated) at the entry to the fuel filter- saves a stretch down to the tank, no restriction to fuel flow when open, and add a wire link to outside the engine bay, you have a remote fuel shut-off?

edit- must type faster!

 

[30boat]

Besides the ballvalve suggested above you can fit an outboard type rubber inline pump.That works well with air and will prime the fuel circuit in no time.

 

[Stoshak]

You can buy a 'squeezy' bulb type pump / non return valve from car spares suppliers. Fitted as standard on some Peugots I think.

Place upstream of primary filter and leave in position. Bleeding of system becomes a 2 minute job.

But you must make sure that the bulb is suitable for diesel. Outboard petrol ones harden and deteriorate internally.

 

[Heckler]

You can buy a 'squeezy' bulb type pump / non return valve from car spares suppliers. Fitted as standard on some Peugots I think.

Place upstream of primary filter and leave in position. Bleeding of system becomes a 2 minute job.

But you must make sure that the bulb is suitable for diesel. Outboard petrol ones harden and deteriorate internally.

On my VP2030 the lift pump was terrible at bleeding so I did what you say, went to the scrappy and bought a Pug squeezy bulb, worked a treat! The connections were the right size so just a question of cutting the line and a couple of jubilee clips
Stu

 

[oldharry]

Outboard type squeezy pump (like Stu - ex Pug from scrappy) solved my fuel lift problem completely. Did try putting a stop valve in, but the fuel tended to run back anyway, so it only partly solved the problem.

 

[emnick]

Check Valve

I use a small brake pipe clamp (not mole grips) on the rubber hose adjacent to the primary filter. normally dont even need to prime. I also fill the filter as best I can with new diesel.
Seems to work well.

 

[lw395]

You should have a shut off on the tank outlet for safety reasons.
Also if the pipework got damaged it is useful to be able to shut it off.
You can get filter heads with priming pump built in, made for transit vans etc.
The Pug part sounds ideal though.

 

[prv]

I have twin filters with changeover valves on a homemade manifold, which also means that when I remove a filter it's effectively isolated by closed valves either side of it. I also have an outboard squeezebulb (although being an afterthought it's in a bit of an awkward place) which works well for filling new filters - much easier than messing about with a can.

Pete

 

[Bilgediver]

Surprised the priming pump does not stop the fuel running back.

Cos it is after the primary pump I expect like so many....

The filter pump is probably built into the filter head so doesn t help once the bowl is removed..


Life would be so easy if primary filters were between the priming pump and the secondary filter!

 

[prv]

Life would be so easy if primary filters were between the priming pump and the secondary filter!

Even easier if they also had an automatic air-bleeding valve like a modern boiler . Turn the engine on the starter for a few seconds and it would fill the filter, bleed the air, and start running.

Till then I'll stick with my twin-filter setup, so that I (hopefully) never have to do this kind of thing under time pressure.

Pete

 

[lw395]

Cos it is after the primary pump I expect like so many....

The filter pump is probably built into the filter head so doesn t help once the bowl is removed..


Life would be so easy if primary filters were between the priming pump and the secondary filter!

Except of course the pump would not be protected by the filter!